1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portal.dao.orm.common;
24  
25  import com.liferay.portal.kernel.log.Log;
26  import com.liferay.portal.kernel.log.LogFactoryUtil;
27  import com.liferay.portal.kernel.util.StringPool;
28  import com.liferay.portal.tools.sql.DBUtil;
29  import com.liferay.portal.util.PropsValues;
30  
31  import java.util.HashMap;
32  import java.util.Map;
33  
34  /**
35   * <a href="SQLTransformer.java.html"><b><i>View Source</i></b></a>
36   *
37   * @author Brian Wing Shun Chan
38   */
39  public class SQLTransformer {
40  
41      public static String transform(String sql) {
42          return _instance._transform(sql);
43      }
44  
45      private SQLTransformer() {
46          _sqlMap = new HashMap<String, String>();
47  
48          DBUtil dbUtil = DBUtil.getInstance();
49  
50          if (dbUtil.getType().equals(DBUtil.TYPE_MYSQL)) {
51              _vendorMySQL = true;
52          }
53      }
54  
55      private String _removeLower(String sql) {
56          int x = sql.indexOf(_LOWER_OPEN);
57  
58          if (x == -1) {
59              return sql;
60          }
61  
62          String newSQL = _sqlMap.get(sql);
63  
64          if (newSQL != null) {
65              return newSQL;
66          }
67  
68          StringBuilder sb = new StringBuilder(sql.length());
69  
70          int y = 0;
71  
72          while (true) {
73              sb.append(sql.substring(y, x));
74  
75              y = sql.indexOf(_LOWER_CLOSE, x);
76  
77              if (y == -1) {
78                  sb.append(sql.substring(x));
79  
80                  break;
81              }
82  
83              sb.append(sql.substring(x + _LOWER_OPEN.length(), y));
84  
85              y++;
86  
87              x = sql.indexOf(_LOWER_OPEN, y);
88  
89              if (x == -1) {
90                  sb.append(sql.substring(y));
91  
92                  break;
93              }
94          }
95  
96          newSQL = sb.toString();
97  
98          if (_log.isDebugEnabled()) {
99              _log.debug("Original SQL " + sql);
100             _log.debug("Modified SQL " + newSQL);
101         }
102 
103         _sqlMap.put(sql, newSQL);
104 
105         return newSQL;
106     }
107 
108     private String _transform(String sql) {
109         if (sql == null) {
110             return sql;
111         }
112 
113         if (_vendorMySQL &&
114             !PropsValues.DATABASE_MYSQL_FUNCTION_LOWER_ENABLED) {
115 
116             sql = _removeLower(sql);
117         }
118 
119         return sql;
120     }
121 
122     private static final String _LOWER_CLOSE = StringPool.CLOSE_PARENTHESIS;
123 
124     private static final String _LOWER_OPEN = "lower(";
125 
126     private static Log _log = LogFactoryUtil.getLog(SQLTransformer.class);
127 
128     private static SQLTransformer _instance = new SQLTransformer();
129 
130     private Map<String, String> _sqlMap;
131     private boolean _vendorMySQL;
132 
133 }